This was largely in response to an August 1879 article written by
Karl Hochberg, Eduard Bernstein, and Carl August Schramm,
entitled "Retrospects on the Socialist Movement in Germany".
The magazine piece advocated transforming the German Social-Democratic
party from a revolutionary to a reformist platform.

It is an unavoidable phenomenon, well established in the course of
development, that people from the ruling class also join the proletariat
and supply it with educated elements. This we have already clearly
stated in the Manifesto. Here, however, two remarks are to be made:
FIRST, such people, in order to be useful to the proletarian movement,
must bring with them really educated elements. This, however, is not
the case with the great majority of German bourgeois converts. Neither
the _Zukunft_ [fortnightly Berlin magazine] nor the _Neue Gesellschaft_
[monthly Zurich periodical] has provided anything to advance the
movement one step. They are completely deficient in real, factual, or
theoretical material. Instead, there are efforts to bring superficial
socialist ideas into harmony with the various theoretical viewpoints
which the gentlemen from the universities, or from wherever, bring with
them, and among whom one is more confused than the other, thanks to the
process of decomposition in which German philosophy finds itself today.
Instead of first studying the new science [scientific socialism]
thoroughly, everyone relies rather on the viewpoint he brought with him,
makes a short cut toward it with his own private science, and
immediately steps forth with pretensions of wanting to teach it. Hence,
there are among those gentlemen as many viewpoints as there are heads;
instead of clarifying anything, they only produce arrant confusion --
fortunately, almost always only among themselves. Such educated
elements, whose guiding principle is to teach what they have not
learned, the party can well dispense with.

SECOND, when such people from other classes join the proletarian
movement, the first demand upon them must be that they do not bring with
them any remnants of bourgeois, petty-bourgeois, etc., prejudices, but
that they irreversibly assimilate the proletarian viewpoint. But those
gentlemen, as has been shown, adhere overwhelmingly to petty-bourgeois
conceptions. In so petty-bourgeois a country as Germany, such
conceptions certainly have their justification, but only _outside_ the
Social-Democratic Labor party. If the gentlemen want to build a
social-democratic petty-bourgeois party, they have a full right to do
so; one could then negotiate with them, conclude agreements, etc.,
according to circumstances. But in a labor party, they are a falsifying
element. If there are grounds which necessitates tolerating them, it is
a duty _only_ to tolerate them, to allow them no influence in party
leadership, and to keep in mind that a break with them is only a matter
of time.

In any case, the time seems to have come.

It is inconceivable to us how the party can any longer tolerate in its
midst the authors of that [Hochberg, Bernstein, Schramm] article. If
the party leadership more or less falls into the hands of such people,
the party will simply be emasculated and, with it, an end to the
proletarian order.

So far as we are concerned, after our whole past only one way is open to
us. For nearly 40 years we have raised to prominence the idea of the
class struggle as the immediate driving force of history, and
particularly the class struggle between bourgeois and the proletariat as
the great lever of the modern social revolution; hence, we can hardly go
along with people who want to strike this class struggle from the
movement. At the founding of the International, we expressly formulated
the battle cry:

The emancipation of the working class must be the work of the
working class itself.

We cannot, therefore, go along with people are openly claim that the
workers are too ignorant to emancipate themselves but must first be
emancipated from the top down, by the philanthropic big and petty
bourgeois. Should the new party organ take a position that corresponds
with the ideas of those gentlemen, become bourgeois and not proletarian,
then there is nothing left for us, sorry as we should be to do so, than
to speak out against it publicly and dissolve the solidarity within
which we have hitherto represented the German party abroad. But we hope
it will not come to that.

This letter is to be communicated to all the five members of the
Committee in Germany, as well as Bracke....
On our part, we have no objection to this being communicated to the
gentlemen in Zurich.